Patients receive liposomal irinotecan intravenously (IV) over 90 minutes, leucovorin calcium IV, and fluorouracil IV over 46 hours on days 1 and 15. Patients also receive rucaparib orally (PO) twice daily (BID) on days 4-13 and 18-27. Courses repeat every 28 days in the absence of disease progression or unaccepted toxicity.